axum-macros: use fully qualified Result type

[matze]

Motivation

It is pretty common to define custom Result<T> type aliases however the typed_path macros generate Result<T, E> on the assumption they are imported from the std prelude. Having the type aliases defined causes errors like:

 #[derive(TypedPath, Deserialize)]
          ^^^^^^^^^
          |
          expected 1 generic argument
          help: remove this generic argument

Solution

Generate fully qualified std::result::Result return types.

[davidpdrsn]

Thanks! Guessed we missed these.

[jplatte]

By the way, it doesn't make this PR less valid but many people now prefer

type Result<T, E = MyError> = std::result::Result<T, E>;

over

type Result<T> = std::result::Result<T, MyError>;

The former allows you to write both Result<Ok, Err> or Result<Ok> without the extra qualification.

[matze]

By the way, it doesn't make this PR less valid but many people now prefer

type Result<T, E = MyError> = std::result::Result<T, E>;

Good point, yes.